Microparticle sorting device that optically, electrically, or magnetically detects the characteristics of microparticles, such as cells, and sorts and collects only the microparticles having a predetermined characteristic have been known (e.g., a flow cytometer).
In cellular fractionation performed by the flow cytometer, the fluid stream (the laminar flow of a sample fluid and a sheath fluid) is generated by an orifice formed in a flow cell. By applying vibration to the orifice, the fluid stream is converted into droplets, and electrical charge is imparted to the droplets. Thereafter, by electrically controlling the direction in which each of the droplets including a cell ejected from the orifice moves, a target cell having a desired characteristic and a non-target cell are collected into different collection containers.
For example, PTL 1 describes “a microparticle sorting device including a microchip having a flow path that allows fluid including microparticles to flow therethrough and an orifice that ejects the fluid flowing through the flow path, a vibrating element for converting the fluid into droplets at the orifice, charging means for imparting electrical charge to the ejected droplets, optical detection means for detecting the optical characteristics of the microparticles that flow through the flow path, a pair of electrodes that are disposed in the moving direction of the droplets ejected into a space outside the chip and that face each other with the moving droplets therebetween, and at least two containers for collecting the droplets that have passed between the electrodes” and serving as a microchip type flow cytometer.